7. April 2008

Permafrost borehole in Larsbreen rock glacier

Contact person for additional information: Håvard Juliussen

Text and photos by Håvard Juliussen

A new borehole was drilled in the Larsbreen rock glacier on 13.-14. March 2008 (see photos below). The operation involved lifting the 2 ton UNIS/Sintef drilling machine and compressor onto the rock glacier and down again by helicopter. The hole is 11.5 m deep and will be instrumented with a thermistor string for temperature monitoring. The hole is cased with a special casing from Geonor, making monitoring of permafrost creep within the rock glacier possible. Jomar Finseth (Sintef) operated the drilling machine (named Majgøril), and Ivar Fredriksen (Geonor), Karin Daniels Amby and Håvard Juliussen (UNIS) participated in the field work. Jørgen Haagensli helped with the logistics.

Figure 1. The Larsbreen rock glaciers. The location of the borehole is marked with a red dot. Photo: Ole Humlum.

Figure 2. We had to remove the blocks in the active layer before we could start the drilling operation. Majgøril ready to drill and Håvard Juliussen in the hole. Photo: Ivar Fredriksen.

Figure 3. Drilling on the Larsbreen rock glacier. Photo: Ivar Fredriksen.

Figure 4. The resulting borehole with special casing for permafrost creep monitoring. Photo: Håvard Juliussen